WG U5000 fault

[Jollywest]

I have a non-working WG U5000 that I could use some help with please, I get nothing on the screen at all. I've taken the monitor out of the cab but still have it connected. When the cab is on I can hear a slight buzz coming from the chassis but there is no orange glow on the neck at all. I've tested the voltage between chassis AC input and the step down transformer and get a reading of 128v. Not sure if this is anything but the wiring schematic and the actual monitor wiring don't seem to match. The 28v cabling has been removed, any ideas why?

[ed12]

did u open the 117vac input to the monitor like that ?
also if u are getting 128vac there
chk your main fuse >after-u-isolate-them-pin's< ie cover them

ed

[Jollywest]

I took the housing off the chassis AC input connector to check the voltage as I couldn't get to the metal part with housing on from the top. When you say main fuse, do you mean chassis main fuse? Because this seems fine   

[ed12]

yes monitor main fuse
if u are getting 128 to them 2 pin's it is beening fed
then from there un-plug power
open 1 side of the fuse
and do a conunity chk on the fuse
in diode range it should b a beep or solid 000
in ohm's low scale it should read 000
if it dose put fuse back in and look at the main load resister
chk it

ed

[Jollywest]

I changed the fuse this afternoon and now get reading of 126.9 VAC.

Testing the continuity:
Diode setting fluctuates between 000 and 001
Low level Ohms setting drops slowly from 1.2 to 0.6 and stayed there (left it for about 10 minutes)

On closer inspection of the tube neck there is slight cracking on the plastic housing on the back, the glass neck tube itself is fine though. Could this cause an issue?

[ed12]

that black i c can be black silicon they use to make sure the neck board dose not fall off..
what we need to do now that u have a good fuse with a load

on that monitor is a b+ chk point

so u hook to that test point and gnd >there-listed-in-the-manual<
under >tp's<,u will cleraly c them
now make sure u are isolated

and follow the tp's=test-point's
on 1 u should have full b+ which drive's the hot horz-out-put
what ever it call's for want's to be there
from there we can get a better idea of the exact problem
rem these chassic need cap kit's and most likely a vert out ic
and as the u5000 is smps driven
u have a total of 3 kit's to put in it
look for ken layton's monitor thread he listed the kit's

ed

[Jollywest]

I've located all the test points on the board but I'm not getting any of the right readings on any them. The first 4 test points say test in relation to AC ground and the other 6, including TP203 B+ say to test in relation to chassis ground. Here's a diagram showing GND point that I used to test, is this right?

click to enlarge

[ed12]

yes the 1 u mark chassic gnd is indeed cold gnd
the other point is your main drive..156..
if u are not getting that
then u need the service kit for the smps.
as i told u before there is 3 service kit's for that chassic

ed

[Jollywest]

Yea I get nowhere near 156 more like 0.3 ! I'll get those 3 service kits ordered.
Thanks for all the help Ed.

[ed12]

hi
glad to hear u are getting the service kit's
now do yourself a fav and follow the install sheet's that come with the kit's to the t.
or u will ordering another kit or 2
and well u are at it
look up ken layton's thread on the cap kit for them
will save u a ton of grief

ed

[Jollywest]

I've emailed Wells Gardner about the kits, I'm just waiting on a reply. I thought I'd look at some info on how to install the kits, just to check if I would be capable of installing the fixes. However when I've gone through the info with the chassis in front of me it seems it has had some of the work done already.
I've put some notes of what I found on the instructions I followed, with some clearer pics of the cleaned chassis:



Horizontal Output Fix:



Vertical Sweep Fix:



Power Supply Fix: (I'm not sure if this has had the fix or not as I'm not sure if these parts are the original or an update, Maybe someone who's done the fix might know?)



Probably still looks like I need to do some of updates but should I do all of them again?

[ed12]

u c pic #! ?
the resistor on the right of the pic is your b+ load resister >it is the one with the band's on the end's but burnt in the middle  white like podwer
not the 1 on the left which is your main smps load input resistor..
the 1 on the right is
2.2 ohm 2 watt
off of it are 2 cap's
u need to replace them
and do the vert-kit
i will b doing a u5000 this week if u want i will
post the kit values
last i looked wg made them nla
this is why i was pointing u to ken's post's
if u can hold on i will give u a scan of each kit ,which btw ken did post for us
and a few other little thing's

ed

[Jollywest]

Thanks, so just to confirm;

1. Replace Resistor & 2 Caps in pic below;



2. Do Vertical Sweep Update fix.

I'll hunt out those posts that Ken put up tonight after work. The info I pulled above was from a link in one of Ken's posts but there must be others then.

* EDIT *

Just had a reply from WG and yes the kits are now unavailable, but he said I may need to change my neckboard. Can you see any damage on the pic below which would warrant replacing it?

[ed12]

the neck board..the brown is just heat
it's very common after 10 yr's of run
just :re-touch-up: the board
that is all we do
plus we rc-cap it at the same time

ed

[Jollywest]

Thanks. I've just gone through every post of Ken Layton's that has the term U5000 in it, and the most descriptive .pdf with aditional notes I could find is the one I downloaded. I've re-attached this .pdf.

Is this not the right one?

[ed12]

yes thats it

1-tda1771  loc u601
1-diode gi  rgp10g >>we use a cross ref<< loc d302
1-resistor 1.2 ohm 2watt loc r303

thats the basic part of the vert.kit
but follow all of the kit's ken posted
i do not know if u know of >nte< ?
but all active part's will cross in there catalog
resistor's and cap's are from normal part's house

ed

[Jollywest]

Just in the middle of building a shopping cart at Mouser, got a cap-kit and the vert. sweep sorted but please can you confirm which resistor and 2 caps to replace, is it these?

[ed12]

that resister yes
and foward of the resister >follow the trace<
is 2 electrolityics,they will be high voltage style 
ie 200+volt
style,they are the b+ supply filter's

ed

[lilshawn]

The reason they say the neckboard needs replacing is cause the tracks de-laminate from the fibreglass board. You just have to really watch the transistors... since they stand out, if they get banged, the legs push through the board and push the tracks right off.

[ed12]

lilshawn

100 % correct,go carefull


33mf-200vdc
100mf-200vdc
them are your cap's
on that line

the resister is 4.7 ohm 3 watt
flame proof

[Jollywest]

The reason they say the neckboard needs replacing is cause the tracks de-laminate from the fibreglass board. You just have to really watch the transistors... since they stand out, if they get banged, the legs push through the board and push the tracks right off.

hmmm.... a bit like this in the pic below ?



Is this going to be a problem?

[ed12]

yes Jollywest
just go carefull

ed

[lilshawn]

The reason they say the neckboard needs replacing is cause the tracks de-laminate from the fibreglass board. You just have to really watch the transistors... since they stand out, if they get banged, the legs push through the board and push the tracks right off.

hmmm.... a bit like this in the pic below ?



Is this going to be a problem?

no, just heat it up with your soldering iron and push the pad down flush with the board. if you keep it up like that vibrations will eventually break the track. if it's flush it will hold for you.

[Jollywest]

Great, I'll do that, Thanks.
I should have everything ordered from Mouser by tonight.
Thanks for all the help. 

[Jollywest]

Hi again, been a while but I only received the components yesterday. I managed to install the fixes last night and finished installing the cap kit this morning.

Unfortunately though I'm still getting the same results - Nothing on screen / No orange neck glow / Low level buzz after a minute or so.

The voltages read roughly the same as they did before;

AC input to Main Fuse > 127
TP103 > 63.0
TP104 > 00.0
TP105 > 63.5
TP106 > Shows 1
TP200 > 00.1
TP201 > 00.0
TP202 > 158.3
TP203 (B+) > 00.5
TP204 > 00.7
TP205 > 00.7

Any ideas?

[lilshawn]

TP106 > Shows 1

be aware tp103 105 and 106 must be measured with respect to the AC ground, not the chassis ground.

TP203 (B+) > 00.5

uuhghh...sounds like a few things:

U101 has pooped out. which is okay, you can tear apart a computer power supply and get another. I've never actually bought one,  but had to replace 6 or 8 of them. we always have powersupplies conk out. i take the chip out and toss the rest. I save them especially for WG chassis.

q101 is flaking out. hard to test. can sometimes test okay, but fail under load. can sometimes SORT OF work. i had a k7500 have a low voltages all around on the output side of the main transformer, but had good voltage on the input side. tried new transformer with no luck. found it was the switching FET after hooking up an oscilloscope to the output and observed the pulses where sporadic and uneven, the scope could hardly lock on to display the wave.

your diodes have gone on you (d106 a/b/c) they are extremely difficult to source, and replacement substitutions (ntc) are terribly unreliable. they are an unusual diode, and testing them is somewhat of a guessing game. dunno what to suggest unless they are obviously shorted or open. I have had these diodes go bad, replaced them with equivalent parts (not the same) and ran good for 2 months, then fail again. robbed diodes from another chassis that had a terminal failure and it's been good since.

shorted cap on the B+ line. check all the brown dipped caps around the flyback, (c721 c723 c716 etc) they should all read open or very high resistance on ohm check. a reading of low or shorted is bad. also check the ones between L100 and the resolution jumper plugs. (c728 c720 c722 etc.)

[Jollywest]

Cheers, that gives me a good few things to have a look at, I'll have a go this aft.

[Jollywest]

be aware tp103 105 and 106 must be measured with respect to the AC ground, not the chassis ground.

Yea I did notice that they should be tested in relation to AC ground. To test these I used the ground cable coming into the chassis AC input CN101, Is this not right?

U101 has pooped out. which is okay, you can tear apart a computer power supply and get another. I've never actually bought one,  but had to replace 6 or 8 of them. we always have powersupplies conk out. i take the chip out and toss the rest. I save them especially for WG chassis.

I found an old PC PSU and found a very similar looking 8 pin IC on its pcb, it has different letters/numbers on it though (see below), can I still use it?
(chassis IC - KA3842B K609B / psu IC - 69A2Y9M LM393P)

q101 is flaking out. hard to test. can sometimes test okay, but fail under load. can sometimes SORT OF work. i had a k7500 have a low voltages all around on the output side of the main transformer, but had good voltage on the input side. tried new transformer with no luck. found it was the switching FET after hooking up an oscilloscope to the output and observed the pulses where sporadic and uneven, the scope could hardly lock on to display the wave.

I may have misunderstood previous posts but I didn't think I needed to install the Power Supply Upgrade kit, which would have included changing Q101. Should I have also done this fix?

your diodes have gone on you (d106 a/b/c) they are extremely difficult to source, and replacement substitutions (ntc) are terribly unreliable. they are an unusual diode, and testing them is somewhat of a guessing game. dunno what to suggest unless they are obviously shorted or open. I have had these diodes go bad, replaced them with equivalent parts (not the same) and ran good for 2 months, then fail again. robbed diodes from another chassis that had a terminal failure and it's been good since.

I tested the Diodes in circuit with a multimeter on the Diode setting. With Negative to Cathode & Positive to Anode all 3 three diodes (d106 a/b/c) read 483.
With Positive to Cathode & Negative to Anode all 3 show a 1 on the multimeter.

shorted cap on the B+ line. check all the brown dipped caps around the flyback, (c721 c723 c716 etc) they should all read open or very high resistance on ohm check. a reading of low or shorted is bad. also check the ones between L100 and the resolution jumper plugs. (c728 c720 c722 etc.)

I tested all the caps on the highest Ohms mutimeter setting (2000K) with the following measurements;
Flyback Caps:
C724 - 008 / 009
C721 - Shows 1
C723 - Infinity
C716 - Infinity
L100 > Res. Jumper Plugs:
C720 - 002
C722 - 11?? then 8?? then shows 1
C728 - climbs from -200 to 1500 then shows 1
C714 - Infinity
C713 - Infinity
C727 - Infinity

[ed12]

Jollywest

Yea I did notice that they should be tested in relation to AC ground. To test these I used the ground cable coming into the chassis AC input CN101, Is this not right?

no

I found an old PC PSU and found a very similar looking 8 pin IC on its pcb, it has different letters/numbers on it though (see below), can I still use it?
(chassis IC - KA3842B K609B / psu IC - 69A2Y9M LM393P)

if it crossed over then yes if not then no

I may have misunderstood previous posts but I didn't think I needed to install the Power Supply Upgrade kit, which would have included changing Q101. Should I have also done this fix?

yes there is a power-supply up-grade kit
it is inculsive

I tested the Diodes in circuit with a multimeter on the Diode setting. With Negative to Cathode & Positive to Anode all 3 three diodes (d106 a/b/c) read 483.
With Positive to Cathode & Negative to Anode all 3 show a 1 on the multimeter.

go to didoe range ,lift 1 end and chk that way,they should read all the same
.5 or .3

tested all the caps on the highest Ohms mutimeter setting (2000K) with the following measurements;
Flyback Caps:
C724 - 008 / 009
C721 - Shows 1
C723 - Infinity
C716 - Infinity
L100 > Res. Jumper Plugs:
C720 - 002
C722 - 11?? then 8?? then shows 1
C728 - climbs from -200 to 1500 then shows 1
C714 - Infinity
C713 - Infinity
C727 - Infinity

best way to do this with out an esr meter is to just replace them

ed

[lilshawn]

Yea I did notice that they should be tested in relation to AC ground. To test these I used the ground cable coming into the chassis AC input CN101, Is this not right?

no, the chassis ground is the same as the green/yellow wire. you need to test the voltage in relation to either the primary or secondary AC sections of the neutral feed of the SMPS power supply depending on where the voltage you measure is... it would be best to let a professional deal with high voltage AC. let's go ahead and ignonre this for now. if this section becomes and issue, we will shotgun the whole section and fix it all at once..

I found an old PC PSU and found a very similar looking 8 pin IC on its pcb, it has different letters/numbers on it though (see below), can I still use it?
(chassis IC - KA3842B K609B / psu IC - 69A2Y9M LM393P)

no. that is a voltage comparator. that PSU is likely an older type. you need the newer switch mode type. they are cheap and light. the older heavy PSU's are linear type power supply (use big transformers) thats why that big honking car battery charger has a huge 10 pound transformer (linear), but your laptop AC adapter (SMPS) weighs a few ounces... but both output 8 or 10 amps of current.

I tested the Diodes in circuit with a multimeter on the Diode setting. With Negative to Cathode & Positive to Anode all 3 three diodes (d106 a/b/c) read 483.
With Positive to Cathode & Negative to Anode all 3 show a 1 on the multimeter.

you must lift out one side of the diode to test, the other parts (caps resistors etc) around it influence the readings. the way the diodes are oriented in the circuit might make testing in-circuit okay, but it's best to remove a leg to test.

tested all the caps on the highest Ohms mutimeter setting (2000K) with the following measurements;
Flyback Caps:
C724 - 008 / 009
C721 - Shows 1
C723 - Infinity
C716 - Infinity
L100 > Res. Jumper Plugs:
C720 - 002
C722 - 11?? then 8?? then shows 1
C728 - climbs from -200 to 1500 then shows 1
C714 - Infinity
C713 - Infinity
C727 - Infinity

again you must lift out one side to test, the other parts (caps resistors etc) around it influence the readings.

C728 - climbs from -200 to 1500 then shows 1

this is the result of the when the voltage being used to test for continuity by the meter is being dumped into another capacitor in the circuit. (shows  negative resistance or climbs up and up) you have to test just the component. you have to remove a leg out of the board (or remove it completely in some cases) and then test.

[Jollywest]

Ok hope this is the right way now...

I've taken each component out of the board to test it.

D106A, D106B & D106C on DMM Diode range read 456 ... Shouldn't it read more like 600?

(I used the croc clips just to hold everything while I took the pic, it read the same without them)

C722 (pic), C720, C719, C728, C724, C721, C723 & C716 all show 1 on the 2000k Ohms DMM setting ...

Does this mean they are all open?

I have managed to source quite a few parts from a site here in the uk which specializes in obsolete & hard to find electronic components. They seem to do all the bits I need to do the Power Supply upgrade, however they are out of stock of SSP6N60 loc Q101, they have a MTP6N60 which looks to have the same spec, will this do instead?
They also do the IC loc U101 and the Transistors loc Q704, Q708, & Q703, but I'm still short of the clip-on heatsink for Q703 and a 10k 10w Cement Resistor loc R104.

* EDIT *

Just checked and they do the Diodes loc 106 a/b/c  albeit 1.9A instead of 3.5A

[grantspain]

can't read a cap without an inductance or esr meter mate,diodes read one way only-if they do they work(can get leaky diodes though)
just fixed one of these little swines tonight

[lilshawn]

Ok hope this is the right way now...

I've taken each component out of the board to test it.

D106A, D106B & D106C on DMM Diode range read 456 ... Shouldn't it read more like 600?)

i don't have one in front of me this second to test what the exact measurement should be, but likely it's fine. test in reverse to be sure they aren't conducting both ways.

C722 (pic), C720, C719, C728, C724, C721, C723 & C716 all show 1 on the 2000k Ohms DMM setting ...

Does this mean they are all open?

yes, and these plastic dipped type should read open or very, very high resistance. if they are low or shorted or obviously burnt then they are bad.. they pretty much work or don't. they often fail spectacularly.

can't read a cap without an inductance or esr meter mate,diodes read one way only-if they do they work(can get leaky diodes though)
just fixed one of these little swines tonight

this is simply a quick and dirty test to sort out not so obvious bad parts. it is by no means conclusive.

[Jollywest]

The diodes do show 1 on the DMM the other way round and looks like an ESR meter may come in handy.

@grantspain - what was the issue with the one you fixed?

[grantspain]

the one I fixed was very simple,just a few caps in the psu section but in the past I have repaired alot of these chassis where the psu section has many components fried(mainly due to remote board being disconnected)

I would suggest the lightbulb trick as a next step to prove the voltages,looks like desolder pins 1 and 3 on flyback then 40 watt lightbulb from pin 3 to chassis earth
Then you can use the voltage guide on wg website to check all the test points

this is for experienced repair peeps though mate,if you are in doubt then don't do it

[Jollywest]

Sorry its been a while... been a tad busy.

I had a look into the lightbulb trick but think I'm a bit out of my depth to do it 100% safely.

Anyways I tested the Chassis & Neck-board for continuity as well as testing most components (out of circuit where necessary) and found a few problems.

Resistors @ loc R512 R120 R619 - No reading
Caps @ loc C109 C601 C611 C728 - No reading or out of tolerance range reading
Transistor @ loc Q703 - No reading
Inductor @ loc L103 - Original Choke Toroid Coil missing and replaced with Sliding Inductor (?) that looks a bit like a Diode.
Zener @ loc Z800 - missing

The only part I'm having trouble finding is the original Inductor @ loc L103. The parts description is CHOKE TOROID 23uH 3A.
I can find one at 25uH 3A, 22uH 3A or 23uH 5A will any of these be ok to use?

Once I get these parts sorted and fitted I was going to test the IC's and check the test points on the board as well.

One other thing and not sure if this is right but I only get a Capacitance reading of 0.03uH from the Flyback Anode suction cup pins to any chassis ground point.