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Toshiba PD1843 - Does this look right?

tonyt76

tonyt76

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Chassis appears to be dead. Checked over everything and nothing looks missing or burnt, all fuses test ok. Several of the flyback pins are not soldered.

CCA5F1F6-2EEF-4D36-AE7B-DB84819FF5FE.jpeg
 
Pads are not connected to anything.

Has the chassis ever worked? Did you buy it untested?
 
@nem I bought it from YAJ. The auction didn’t state if it was working or not sadly.
 
Definitely has been touched.

The silicon has also been removed.

I'd reflow all those flyback pins and then go from there.

The "burnt" look you see is just flux, get some IPA and you'll be able to clean it out.
 
Check the fuses. Check the HOT. Check the board for roasted components.

Chassis off YAJ are hit or miss. I've bought... maybe 5? Only one worked.
 
kazuo said:
Chassis off YAJ are hit or miss. I've bought... maybe 5? Only one worked.
Click to expand...

A lot of things are now.... I've purchased I think 4x CPS3 mobos - only 1 has worked. 4x Naomi's (1 naomi2) - only 1 has worked.
 
My hit rate on pretty much everything else on YAJ is close to 100%. Not sure if I'm just lucky or what.

Chassis boards though? Forget it, I just expect them to be broken.
 
kazuo said:
Check the fuses. Check the HOT. Check the board for roasted components.

Chassis off YAJ are hit or miss. I've bought... maybe 5? Only one worked.
Click to expand...
@kazuo thanks, can someone point me to where the hot is on this chassis?
 
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Quick question not related, the flyback has a Focus pot and the neck board also has a pot labeled Focus. Which one should be used?
 
The one on the flyback. The pot on the neck board is for dual focus tubes and is not used with this tube.
 
No, that's not right. If you have the standard Tosh tube paired to a PF (A68LTF356X) you can further adjust focus with it. The difference is very subtle, but it is there. It's due to the voltage divider that has been installed in the neck.

On the Beijing Matsushita tube the pot is useless.

tonyt76 said:
@nem I bought it from YAJ. The auction didn’t state if it was working or not sadly.
Click to expand...

I'm not surprised. The only reason why I could see someone leave the flyback like that would be because they were trying to fix the chassis by replacing the flyback.
 
I can send it out to Sharp, but if I can try anything myself, I am pretty decent at desoldering/soldering. I just need advice on what to test/look for.
 
nem said:
No, that's not right. If you have the standard Tosh tube paired to a PF (A68LTF356X) you can further adjust focus with it. The difference is very subtle, but it is there. It's due to the voltage divider that has been installed in the neck.
Click to expand...
Really? I have a original Tosh tube with the PD1843 chassis and this pot has zero effects on the focus.
 
Well, now you at least know it can make a difference on the tube that you have. Doesn't mean it will make a difference :p
 
tonyt76 said:
@kazuo thanks, can someone point me to where the hot is on this chassis?
Click to expand...

Should be on the giant heatsink, I want to say it's on the side closest to all the yoke connectors but it's been a while since I messed with one.
 
I know that some japanese chassis they don't do repairs anymore and they file up and sell in some amusement that has closed
 
Throwing in the towel on this one and sending it to Sharp. I have no idea what I'm doing :P
 
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