Monitor makes crackling sound and pic goes black

[kernow]

Hi,

I've got a bit of an intermittant problem with a 19" Mitsubishi Diamond Pro 900u (my baby). The picture flicks off (screen goes black - no picture) and then comes back on really quickly. Sometimes there is some electrical crackling noise too. It's just gone out of warranty (typical!).
I've talked to a hardware guy at work and he recons it might be either capacitors drying out which would need replacing or the HT cap needs cleaning. First question is does this sound about right?

I'm not an electrical person so second question - is this something I can read up about an sort myself or is it best to take it to a pro - if so is this worth it cost-wise (it did cost quite a lot) or should I wait for it to give up the ghost and then look for a replacement?

Any help/suggestions greatly appreciated.
Thanks,
Seth.

 

[edfair]

You're losing HV. Take it to a pro. Lethal voltages inside.
Can be from dirt where HV is tracking to ground, but let the pro do it. Ed Fair
unixstuff@juno.com
Any advice I give is my best judgement based on my interpretation of the facts you supply. Help increase my knowledge by providing some feedback, good or bad, on any advice I have given.

 

[Mulga]

Just want to reinforce what Ed has said. Those lethal voltages are present even when the unit is switched off and unplugged. DO NOT TAMPER!! All things are possible except skiing through a revolving door.

 

[kernow]

Thanks guys - don't want to cook myself. I'll try and find someone to have a look at it.
Thanks again.

 

[desertworker]

Uh...not to butt in, but remember to check for the simple stuff...like a loose power plug in the back of the monitor.
I had a problem with a monitor at a client site very much like the issue you are describing, and it drove me crazy!
I was about to send it back, but something made me go back and take a fresh look; I started wiggling cables...and the fix was easy-seat the power plug more firmly!!!

Hope it saves you some moola....

 

[kernow]

Hi - Yeah have checked the power cable is firmly in -might replace it just to make sure though. I got a price for fixing it from Mitsubishi UK £140 + VAT at 17.5% + £55 delivery + VAT. It does include £20 of parts which is a real bonus. Something tells me they don't want to repair them. . . .
Anyway - thanks for all the replies on this.

 

[crwpulsar]

The crackling sound could be the HV transformer packing in or one of the big capacitors being damaged.By the sounds of your problem is the capacitors which are soldered onto the board so thats why they dont want to repair it as it will involved either replacing the PCB(not likely) or removing and resoldering new components to the PCB.Which is why Ed and Mulga adviced to get a pro to look at it as the capacitors hold the high voltage for the tube.
David

 

[Wassercrats]

I know this is kind of old, but I have a new (three days old) Mitsubishi DiamondPoint SB70 that did the same thing three times last night, all within a few minutes. I increased the ventilation by removing a box that was next to it and waving some air on it and it was good for the next half hour, when I shut it off.

I guess I'll forget about using one of those shelves that sit on the monitor, unless I put a fan under it.

I have a six foot extension cord piggybacked with the surge protector cord, which also might be the problem. I intend to replace the six foot cord with a one foot adapter, but the one I bought doesn't seem to work (except with my lamp).

 

[kernow]

I've had a repair guy (friend of a friend) have a quick look at it and it looks like it is a daughter-board causing the problem. His guess is that the problem is being caused by solder joints. Could be that yours has the same thing?

Hope this is of help.

 

[Wassercrats]

I haven't had the problem since, and I just ordered a surge protector with an 8' cord so I don't have to use the extension cord, and I raised the monitor so even the computer doesn't block the air flow. I don't know what caused the problem, but it seems to be gone... but I'm considering a fan and a grounded mat too. And I'm keeping the box, just in case.