High Ability Computer HA-1204 labeled 1209C

[jscipione]

Can someone help me to identify this power supply from a High Ability Computer HA-1204 labeled 1209C ? It’s a specialty computer created apparently in 1993.

I can’t find any information about this computer anywhere. It is a portable luggable Compaq style computer with a 8.5” VGA CRT and it takes a standard AT motherboard.

You may recall I was looking for one of these a while back, well I found one but the power supply on it is quite dead.

Before I begin to try and repair this thing I wonder if anyone can provide me with any information.

Thanks

 

[jscipione]

I replaced all the electrolytic caps on the board and the fuse. I’m getting line voltage going in but no voltage coming out. No fan spin. Tried hooking up an MFM HDD and 486 motherboard in case it needs a load but it didn’t make a difference. This power supply seems to supply all the voltages for AT and the CRT so I can’t easily replace it with another part.

 

[Chuck(G)]

Move next to the semiconductors--the power diodes are a good place to start. Then transistors, then ICs.

 

[polpo]

Sorry to necropost here but I have the same luggable PC case with the same PSU. After replacing a couple obviously bad caps, the rails going to the AT connector measure fine but the voltages going to the CRT seem bad (only reading a couple volts on both of those rails). @jscipione did you make any progress in fixing this power supply?

Or if there's a way to determine what voltages the CRT wants, I could use a different power supply instead. Any ways to determine that? Searching identifying numbers from the CRT board gives me nothing and searching the power supply brings me to this thread.

 

[jscipione]

I’m afraid that you’ve gotten further than me with this power supply. I replaced all the caps but I’m still getting a blown fuse and so I’m not able to get voltages out of either AT connectors. There’s no way to use a different power supply on the CRT side since it is supplying the high voltage.

Can you take a picture of C61 just behind the AT connectors? That is bodged on mine and I’d like to know what that is supposed to be connected to.

Can you measure the voltage drop between the fuse F1 and the ground screw that’s right next to it? Mine is fluxating between 0 and 9V.

I verified the main switching transistor and shockey diode connected to the large heatsink in the middle are ok by desoldering them.

 

[polpo]

I’m afraid that you’ve gotten further than me with this power supply. I replaced all the caps but I’m still getting a blown fuse and so I’m not able to get voltages out of either AT connectors. There’s no way to use a different power supply on the CRT side since it is supplying the high voltage.

Can you take a picture of C61 just behind the AT connectors? That is bodged on mine and I’d like to know what that is supposed to be connected to.

Can you measure the voltage drop between the fuse F1 and the ground screw that’s right next to it? Mine is fluxating between 0 and 9V.

I verified the main switching transistor and shockey diode connected to the large heatsink in the middle are ok by desoldering them.

C61 is a 100nF ceramic capacitor. Photo attached. I measure about 60VAC between the fuse and ground.