Working on a G07 again, blew it up again it seems. **Losing power**

[Mauzy]

Been out of the arcade scene for a couple months and decided to come back to an old project. had a G07 working moderately well (poor convergence, couldn't dial in vertical sync) but it was "working" nonetheless. I had the game off to look at something on the chassis, went to plug in the chassis' power and saw a spark toward the back of the chassis. Somehow I must've knocked the switch as the game had power. The monitor shutdown immediately and won't turn back on. Fuses are good, I found that D505 seems to be blown (MM shows current flowing in both directions...). Looked at a schematic and it says that D508 is a 1s2473h or ls2473h, (I don't know naming conventions) neither of which can I find any information about on the internet.

Essentially, what is the proper replacement for this diode?

[lilshawn]

if you remove the diode and look carefully at the body it should have something printed that might be more of a traditional number for it. the number given in the schematic might be just an electrohome #



this diode is a 1n4007 even teeny tiny zener diodes have a number printed on them... take a look, you might be pleasantly surprised.

[Mauzy]

Nah, its one of those glass deals with the orange core. Completely blank...

[lilshawn]

Sounjds like a zener... They do pass voltage both ways.

On diode test they should read .5 or so volts one way and  Something the other (varies by diode)

It should have something printed on it... Even just "6V1" is something

[Mauzy]

hmm. That is how it tested, about half a volt one way, similar the other. I tested another diode with the same package that was nearby and it only passed voltage one way which is what led me to believe this one was bad..

There is no writing whatsoever on this component. Perhaps the manufacturer cheaped out? 

[lilshawn]

according to the component layout silkscreen on the GO7-02 manual it's not zener it's a standard diode. as far as what it is...

i have no idea where they are, but the manual says D1401 and d1301 are the same diodes... compare them readings wise and see

EDIT:

the G07-04 maual says the same diodes (D1401 ans D1301)are 1SZ473H which is a zener perhaps it might be a compatible cross?? not sure what version you have there... but it's another possibility.

[Mauzy]

the G07-04 maual says the same diodes (D1401 ans D1301)are 1SZ473H which is a zener perhaps it might be a compatible cross?? not sure what version you have there... but it's another possibility.

More than likely I misread 1SZ473h for 1S2473H. A 2 and a z look awful similar on a grainy PDF.

[lilshawn]

looks like you have a later revision chassis.

looks like they changed from an 1S2473 to a 1SZ473... electrically they operate the same, but one will be a conventional semiconductor diode and the other a zener.

[Mauzy]

Neither of them can be found on google, except in this thread

[lilshawn]

I have a cross reference book at the shop, I'll take a look tomorrow and see what I can find

[lilshawn]

i have an older NTE cross reference book from 98, it lists the 1S2473 replacement with an NTE177

the datasheet is here: http://www.nteinc.com/specs/100to199/pdf/nte177.pdf

note: this is the standard semiconductor diode based on the original 01/02 series... do you know what version the board is?

EDIT: i don't have the 1SZ473 # in my book it might have been a short run item replaced by something else.

[Mauzy]

I'm not sure of the revision, sticker on the side just says G07-CBO, October 1981 the other side says January 1982.

BTW I appreciate all of your help!

[ed12]

i get 8 hit's with google on this part #1SZ473H
as i rem it is a type :b: glass diode
high voltage clamp

links
xxx.arcade-museum.com/.../Williams_Type_B_19in_Color_Monitor_(16- 3000-100B)_Jan_1982.pdf

etc
there is 8 link's
and 5 pdf's
also nte dose  not cross ref it,they did how ever at 1 time do it when they were ecg

ed

[lilshawn]

here ed, lemme get that for you...

http://arcarc.xmission.com/PDF_Monitors/Williams_Type_B_19in_Color_Monitor_(16-3000-100B)_Jan_1982.pdf

[ed12]

it stuck in me mind to double chk it again
481-0149 Si diode, 1SZ473H v D508 481-0231 Zener diode, RD20EV2 D701 481-0160 Si diode, 1S1887A D901 481-0160 Si diode, 1S1887A D902 481-0160 Si diode, ...
1s is from back in the day before we went 1n....the z dose mean zener
as a rule without pulling out the g07 stuff if my mind is not leaving me it is in the :damper: section of the :hot: transistor ?? before we used the now default combo pkg transistor/diode

ed

[Mauzy]

Well damn, NTE177 is something I'm gonna have to order. Unless I can scrounge it out of something  

EDIT: So how is a "compatible" diode determined? Does the replacement have to EXACT in every specification, or is there some tolerance?

EDIT AGAIN: Scrounged a replacement, still nothing. Poked around with the multimeter a little more and founf that there is no power AT the fuse, I checked the fuse and its fine. Something between the power plug on the chassis and the fuse seems to have gone awry.

[Ken Layton]

It appears that Electrohome has some typographical errors in the manuals regarding this 1SZ473H and 1S2473H diode. The schematic in all versions shows it as a plain diode. I'm going to have to say it appears somebody ---fouled up beyond all recognition--- up in the manuals.

I believe the diode number in all revisions of the G07 manual should be 1S2473H which is a switching diode that crosses to these numbers:

1N4148

NTE 177

NTE 519