Tulip TCX17 AT Power supply \ VOGONS

Tulip TCX17 AT Power supply

Topic actions

First post, by PD2JK

Posted on 2023-09-19, 14:59

PD2JK Offline

Rank Oldbie

Rank: Oldbie
Posts: 1225
Joined: 2018-05-28, 08:40
Location: JO32GE

Dear Vogoners,

I'm trying to repair a dead Tulip TCX17 AT power supply. I already replaced that capacitors because they were leaking. I tested the remaining caps on ESR and capacitance, they are fine.

At the moment I am running the power supply with two old HDDs as load. The +5V rail is ok, but the +12V starts with 8V and now 10 minutes later, it reached 11,96V and is still rising a bit.

It looks like a transistor is having trouble to deliver the voltage? Does anyone have experienced such behaviour?

has all kinds of stuff

Reply 1 of 4, by PD2JK

Posted on 2023-09-22, 17:23

PD2JK Offline

Rank Oldbie

Rank: Oldbie
Posts: 1225
Joined: 2018-05-28, 08:40
Location: JO32GE

Replaced everything with a TO-220 package (MOSFET, thyristor, diode IC). Also measured all the diodes and resistors, all good.
It's up and running again.

The attachment DSC_6315.JPG is no longer available

(286 16MHz, 1MB RAM, WD90C31-LR 1MB VGA card)

I was amazed how fast I got all the stuff from Digikey. Within 44 hours the package went from the US to Köln, Germany, to NL.

has all kinds of stuff

Reply 2 of 4, by zzgus

Posted on 2026-07-15, 09:25

zzgus Offline

Rank Newbie

Rank: Newbie
Posts: 47
Joined: 2018-05-25, 16:28

PD2JK wrote on 2023-09-22, 17:23:
Replaced everything with a TO-220 package (MOSFET, thyristor, diode IC). Also measured all the diodes and resistors, all good. I […]
Show full quote

Replaced everything with a TO-220 package (MOSFET, thyristor, diode IC). Also measured all the diodes and resistors, all good.
It's up and running again.

The attachment DSC_6315.JPG is no longer available

(286 16MHz, 1MB RAM, WD90C31-LR 1MB VGA card)

I was amazed how fast I got all the stuff from Digikey. Within 44 hours the package went from the US to Köln, Germany, to NL.

I know it's a quite old thread but I'm having also problems with the popwer supply.
Can you tell me exactly what was your problem and what did you do please ???

Thankyou
Gus

Reply 3 of 4, by TELVM

Posted on 2026-07-15, 13:07

TELVM Offline

Rank Oldbie

Rank: Oldbie
Posts: 1042
Joined: 2012-02-26, 14:51
Location: Spain

Found a pic of the Tulip TCX17 guts in this Vogons thread

file.php?id=143638&mode=view

From what I understand, PD2JK's PSU was dead.

After recap it came alive, but +12V voltage regulation wasn't OK. (Perhaps the +12V rectifier diode was defective).

Then he replaced transistors and rectifier diodes with fresh ones in TO-220 package, and that solved the problem for him.

Let the air flow!

Reply 4 of 4, by PD2JK

Posted on 2026-07-16, 09:06

PD2JK Offline

Rank Oldbie

Rank: Oldbie
Posts: 1225
Joined: 2018-05-28, 08:40
Location: JO32GE

Yes, all correct like TELVM said. ^^

By replacing various components it was a bit of a 'shooting with buckshot' approach, but it worked.

has all kinds of stuff

Go to top of page Go to top of page

Back to General Old Hardware