DELL 2001FP trouble

[+DjayBee]

While not being used for some six months my DELL 2001FP decided to break down.

 

When I turn it on, the power LED flashes for a split second and then the LED of the power supply fades to dark.

The obvious first guess was the power supply, but replacing it did not help.

 

Now I disassembled the unit completely.

 

The main logic board with connected display panel seems to work.

The power LED lights up and shortly after the LED which shows the active input turns on as well.

 

As soon as I connect the inverter board to the main board, the error comes back.

This happens already if I only connect the inverter itself to the main board - without having it connected to the panel's backlights.

 

What is more probable?

- The inverter board is bad and pulls too much current (even without connected backlights).

- The power distribution on the main board is defective and cannot deliver enough power.

 

Any (at least educated) guesses are welcome.

[_The Doctor__]

recap the boards replace the fuse and then start your troubleshooting, though you can replace the stuff lock stock and barrel, many that you buy are also near end of life...

[+DjayBee]

There is no visible damage on the boards.

All caps have flat tops (no swelling) and none shows signs of leakage.

Edited January 25, 2021 by DjayBee

[bbking67]

likely needs a recap... look for bulged or leaking capacitors... no guarantee, but otherwise an old monitor like that is probably not worth fixing.  

 

[tmp]

15 hours ago, DjayBee said:

This happens already if I only connect the inverter itself to the main board - without having it connected to the panel's backlights.

 

What is more probable?

- The inverter board is bad and pulls too much current (even without connected backlights).

i think inverter will (should) shut down if there is no load connected, even if it's not a proper one (e.g. one tube is damaged) so testing it this way might not lead to the correct conclusion

[+DjayBee]

7 hours ago, tmp said:

i think inverter will (should) shut down if there is no load connected, even if it's not a proper one (e.g. one tube is damaged) so testing it this way might not lead to the correct conclusion

"shut down" sounds like it would afterwards not draw any/much power.

Correct?

This sounds like the opposite of what I believe to observe.

 

After the power supply gets "dark" it will not deliver any power until I replug it in the wall socket.

My interpretation is therefore that it gets overloaded (or short-circuited) and the dimming and shutdown is the result of a saveguarding mechanism.

 

At the beginning I supected a dried out capacitor which (as far as I understood) can result in a short circuit.

But all caps visually look good - no bulges, no leakage - so I meanwhile doubt this.

Also if a cap in the power distribution part of the mainboard would be the problem, then (also from my very limited understanding) it would always short-circuit and not only when another board has been plugged on top.

 

The inverter board has two caps which also do visually look good. (Not knowing if this is a valid test) I measured the resistance of them with a multimeter and got 20-40 kOhm.

 

 

[bbking67]

With nothing visible you would need an ESR tester to test the caps in circuit... with nothing visible (or smellable) it could be a number of other things.  You've got to ask yourself if its worth it.

 

In my city's buy sell site there are a couple of these cheap.. one asking $40 Canadian and another for free (with known bad caps).

 

Is there something special about the Dell 2001FP?

 

 

[chevymad]

Certain models of the dell 2001fp are 15khz compliant. 

6 minutes ago, bbking67 said:

 

 

Is there something special about the Dell 2001FP?

 

 

 

[manterola]

15kHz support in older models and s-video and composite input, I guess

[bbking67]

Ahh yes that makes sense... well follow the power.

[gilsaluki]

24 minutes ago, chevymad said:

Certain models of the dell 2001fp are 15khz compliant. 

 

cap kits are available for these Dells.  I did one and it worked great.

[BillC]

11 hours ago, chevymad said:

Certain models of the dell 2001fp are 15khz compliant. 

Good to know, according to some info I found anything up to June 2005 are supposed to have sharper 15khz display, later ones reported to be a bit fuzzy. I have a December 2003 model with optional soundbar, in addition to composite/s-video/RGB it also has DVI-D.

 

[_The Doctor__]

Yes very nice in all respects except the 16 millisecond lag...

[Mrarkus]

1 hour ago, _The Doctor__ said:

Yes very nice in all respects except the 16 millisecond lag...

 

I'm a huge fan of 2001FPs, have a couple and have used them for a long time with everything from Amigas and STs to 8-bit. With that said, you point out a very real issue with old LCDs like these. I have now switched my 8-bits over to modern Dells thanks to Sophia 2 and RetroTINK, and to my eyes the difference is very noticeable between a 4-5ms screen and the old 2001FP.