Help with 14" Sanyo monitor

[Grauwulf]

Hey, hopefully someone has one of these 14" Sanyo monitors and can help me out. I am trying to find out what the P/N is on the voltage regulator. I have the Atari manual for this monitor (the only manual I can find for it) and it does not have a part number for it in the parts list or on the schematic.

Can anyone help me out?

[Kevin Mullins]

Is there anything legible on the transistor itself?
(you probably already looked, but I thought I'd ask anyways)

Is it the TM-157 manual you have?

[Grauwulf]

Yes, it is the TM-157 manual.  And I have checked the installed part for a P/N and I'm not convinced it is the right part.

[Kevin Mullins]

Don't quote me on this just yet....
Maybe someone else can verify this.

Diagram and schematic shows TR981, I believe that should be 901, therefore in the parts list it would then be the Q901. (which doesn't show anything but the Sanyo part number)

But researching some "kits" for the Sanyo 14" I found.....

Q901 - MPSA06


EDIT: I e-mailed Bob Roberts about this one and all he could tell me was the the A06 designation was NOT a regulator. I did an NTE cross reference and that particular one came up as an amplifier. So I guess I'm wrong about that one. 

Anybody else have any ideas?

[Grauwulf]

Well I'm looking at TR981 on the schematic, which looks to me like it should be the voltage regulator. No part number listed on the schematic or parts listing. The installed part is a 2sc1030 which does not appear to be a voltage regulator, but an audio power amplifier transistor (NTE 280). If that's the right part, great, I will replace it with the same. I just want to make sure before I order one since it's not a part I have on hand.

[Kevin Mullins]

OK...I did a little more poking around and compared the 14" schematics with the 19" 20EZ schematics. (I'm a little more familiar with that one)
Seems they are both of the same basic design and the 20EZ manual was a little more informative.

On the 20EZ - Q901 is the current limiter which would be in the same location as your TR981 on the 14". (should be on the large heatsink)

20EZ- 2SD1090 - NTE2307 - High Power Gain Amp
14" - 2SC1030 - NTE280 - Audio Power Amp

So essentially the TR981 part on yours should be the correct one as they both cross to similar components of similar purposes.

But I noticed on the 20EZ schematic that IC601 is the voltage regulator in the power supply section. (LA5112N)
The 14" also has an IC601 in the power supply section. (LA5110)

Bad news is neither of them crossed on the NTE cross reference on-line.
But I'm sure we can dig (google) enough to find it.

[Grauwulf]

Yeh, I was looking at IC601 on the schematics and wasn't sure if it was involved or not. I guess I need to go on the hunt for one of those too. My regular suppliers don't carry it.

[Kevin Mullins]

Yeah, I was trying to find a datasheet on both of those IC 601's last night and all I found so far was versions in Chinese. (of course I was dead tired by then, so maybe it wasn't Chinese afterall  )

I'll continue to hunt.

[Ken Layton]

The reason you can't find the LA5110 or 5112 is because they are obsolete and were discontinued over 20 years ago. That's why they no longer cross to an NTE number. You're going to have to try to find new-old-stock and that's going to be tough.

[Grauwulf]

That is pretty much what I was afraid of.

[Ken Layton]

Those critical power supply regulator ic's have been impossible for me to find. If the monitor is not going to be used for Nintendo games, then I throw in either an 8liners (Jen Shinn) or Wei-Ya universal replacement chassis and use it for JAMMA games.

[Grauwulf]

Well it's not my monitor, it belongs to a customer. Right now the B+ is all over the map, sometimes it is higher than it should be and some times it is lower. The B+ adjustment pot does not appear to do anything at all. I still need to pull the pot and test it to make sure it's in spec, but I have a sneaking suspicion that the problem does not lie there.