Star Wars Racer - Hitachi Monitor Failure

[Didj]

Hello,

I have a Star Wars Racer unit (not the deluxe), model STD-POD-GPI with:

CRT: Hitachi
Type: A78LCU30x

Chassis has the part number 025 1486-001

The problem is that the monitor is completely dead. I cant see any glow or signs of life. I have reseated the neck board, checked power etc, but nothing is jumping out as a failure.

Are there any resources I can study on this particular monitor type? Searching the forum did not yield much for this particular model. Trying to find a place to start on the debug.

Thanks,

Didj

 

[Ordyne]

Post a picture of the chassis, your references there are just for the tube. Most likely to be a sanwa 29e31s, possibly a Nanao too.

 

[Didj]

Hello,

I took the following pictures of the chassis. Also, while I was in there I noticed the power supply transformer looks like it might have gone bad. But, you were right on checking the chassis. Turns out its a 85x0414-001D.

Here's what I was able to find out after you're suggestion

MODEL: WGM3332-U0TS65G
DESCRIPTION: 33" U3000 VGA UNIV
CHASSIS: 054A3301-001
NKBRD: 054A0583-002
CRT WG P/N: 088X0392-506

Power Supply Board with the transformer that looks suspicious
PCB Number: P756 POWER SUPPLY
Model # 33K3301
Monitor Part # WGM3332-U0TS65G
Monitor Replacement: None Mentioned
Comments (Replacement): None Provided

Searching for a schematic now as well.

Suggestions welcome and opinions on the power supply transformer.

Didj

 

[Ordyne]

Wells Gardner U3000, it's one of the few WG's I've never worked on so can't help you a lot. Isolate the b+ and work from there if it's anything like a u2000 or u5000

 

[Ohmerone]

Hello,

I took the following pictures of the chassis. Also, while I was in there I noticed the power supply transformer looks like it might have gone bad. But, you were right on checking the chassis. Turns out its a 85x0414-001D.

Here's what I was able to find out after you're suggestion

MODEL: WGM3332-U0TS65G
DESCRIPTION: 33" U3000 VGA UNIV
CHASSIS: 054A3301-001
NKBRD: 054A0583-002
CRT WG P/N: 088X0392-506

Power Supply Board with the transformer that looks suspicious
PCB Number: P756 POWER SUPPLY
Model # 33K3301
Monitor Part # WGM3332-U0TS65G
Monitor Replacement: None Mentioned
Comments (Replacement): None Provided

Searching for a schematic now as well.

Suggestions welcome and opinions on the power supply transformer.

Didj

You shouldn't need a schematic.

keep it simple, caps connection and if tube is good then a flyback

if all you need is caps, looks like the fly has a crack in it by the pots.

it won't kill the chassis with just a crack ut will mess with

the focus and screen brightness.

Carefull removing the pin amp transistor

by the power supply, easy to brake a leg.


measure the dc at the ps connector before you replace all the e-caps

except for the filter cap. compare the dc before and after, most cases the B+

doesn't need adjusting.

easy to cap chassis.
wells has the manual.

 

[Didj]

Thanks, I finally had some time to test some voltages based on the pointers. I would have bet the power supply board was bad, but I measured at the chassis and I am getting
Red to ground: 22.7 VDC
Orange to ground: 180.4 VDC

I am taking this to mean the power supply board is delivering enough voltage to the chassis, so now I am looking at the chassis.

I'll examine the flyback, but as you said, it shouldn't kill the monitor, and I am getting zero out of the monitor and no neck glow.

Any things to zero in on given the complete lack of response from the monitor?

Thanks,

Didj

 

[Ohmerone]

Thanks, I finally had some time to test some voltages based on the pointers. I would have bet the power supply board was bad, but I measured at the chassis and I am getting
Red to ground: 22.7 VDC
Orange to ground: 180.4 VDC

I am taking this to mean the power supply board is delivering enough voltage to the chassis, so now I am looking at the chassis.

I'll examine the flyback, but as you said, it shouldn't kill the monitor, and I am getting zero out of the monitor and no neck glow.

Any things to zero in on given the complete lack of response from the monitor?

Thanks,

Didj

B+ is to high.

Do you have that much on the collector of the HOT.

need your 22v to 12 zener z700 cathode voltage for the HV ic

with no drive from ic the B+ will max out dc from no load.

or your in shutdown that's where the ic has shut off the osc

and no drive from pin 12.

wells have a voltage chart..

If you put the bulb on the B+ from the PS then it will drop the dc

so the chassis can start up.

Any burned up or faded color bands on the resistors?

can be a clue theres a part over heated it.

any holes in the flyback side of fly.

If original caps then should replace them what a 1998 chassis

but you can check around for anything obviously bad.

Heater comes from the fly so no hv then no heater.