Stupid Hantarex Polo!

[timply]

Quick back story. I bought a MK2 with a Hantarex Polo, it didn't work. Recapped and replaced the flyback, it works! Hooray! Life is good.

Now, 6 months later, I turn the game on the other day and the sound comes on but no picture. I turned it back off and on again and it works.. ok thats weird.

Unfortunately that was the last time it worked. The B+ is reading 1.6 what is my next course of action to take?

[grantspain]

one of the easiest chassis to repair

is the chassis ticking?

[timply]

Nope, I'm not hearing any ticking.

[grantspain]

so no ticking means that the ocp has not kicked in, the issue could be bad power connection, bad solder joint, fuse holder not contacting correctly on chassis
first thing to test is power input to the chassis

[timply]

Alright, the first thing I decided to check was the voltage of the power wire going to the monitor. There are 2 power wires and a ground, purple/yellow, green and solid purple. I unhooked it at the connector just before going into the monitor and tested them there. The purple/yellow wire is giving me 68 ac volts and the solid purple is giving me 60 ac volts. Are those correct? They sound rather low to me.

[grantspain]

reading on ac between the two purple wires you should expect 120vac if usa chassis, 230vac if european version

[timply]

Ok, so I should test the 2 purple wires together? I tested each other separate using the metal chassis as a ground.

Edit: OK, I am getting 120v at the connector. I sure didn't wanna take this heavy monitor out.. but away I go. I'll let you know what I find.

[timply]

I checked solder joints starting from the power connector onward, everything looked good. I refreshed a lot of the dull looking joints. I checked continuity as well as I could and everything seemed good. (I'm not the best at understanding traces either, btw)  What is next thing I need to check for?

I also noticed the big filter caps, I didn't change those as they were not in my initial cap kit, should I order a couple and replace those while I have the monitor out?

[grantspain]

yes its a good idea as they are probably very old, like i mentioned before remove the chassis fuse and inspect for any arcing- pinch the holder blade together a little

when checking ac voltage you meter between both ac lines and not earth, dc voltages are earth/common/ground to dc

where were you reading the b+ btw, i use one of the centre two pins of the deflection yoke connector and flyback heatshield as my meter points- i would expect usa b+ of about 130v

[timply]

Ok, popped out the fuse and pinched the holders together to make sure it has a tight fit. B+ reading 0.0. I am currently testing at TP6 and grounding using the metal chassis bars that surround the pcb. Now, when you say the deflection yoke connector, are you talking about the 2 green 6 pin connection points on the pcb? Do I test at one of the 2 center pins of the unused connector? I'm sorry, I'm not 100% familiar with the names of everything.

I doubled checked continuity on everything in the power supply area and looked for any broken traces or cracks throughout the whole board. I also reflowed the ceramic filters and checked continuity on them. The board actually looks pretty good shape except for a few dark spots where I'm assuming its getting pretty hot.

[grantspain]

yes the 6 pin connector, the centre two pins are a link- put the + probe into the pin gap there and use flyback heatshield for -

you should read around 130vdc, if you have no b+ then either the chassis is in ocp or the power supply section has failed

[timply]

I tested the b+ using the deflection yoke connector and heat sink shield and its reading 0.0v 

[grantspain]

depends on how safe you are electronically but the next step is isolate pin 3 of the flyback and add a 40w lamp to the solder pad and ground, if that works and shows stable b+ you then resolder the flyback pin and then isolate the HOT and add the lamp to pin 1 of flyback

really odd to have 0 b+ though, normally it goes very high and the ocp kicks in

[grantspain]

btw don't attempt to fix this if you are not good with electronics- there are some very nasty voltages on chassis, much worse than HT

[timply]

Yea, as bad as I hate to, I might just send it off for repair, I appreciate everything, you've been really helpful!

I'll look over it one more time and try to find a bad solder joint or broken trace or something.