Possible 2SD1802 replacements?

[lexwalker]

Monitor was a Dell E151FP. Symptom is 2 seconds to black. The transformers seems to measure fine. Found two blown transistors at the inverter section. Now the problem is that its kinda hard to find 2SD1802 especially in TO-251 package (found mostly TO-252 ones). Thus the question is, can I safely replace them with another/alternative transistor such as...

- 2SC5707 (TO-251, closer to original specifications but higher current)
- MJE3055T (TO-220, lower frequency)

Are there any other transistors besides the ones I've listed above, that can be considered/recommended?

Also do I have to replace the other two 2SD1802 transistors on the other side with the those alternative replacements also (as to match both sides)?

[selldoor]

Re: Possible 2SD1802 replacements?

It would be a great help if you were to update your profile with country and mains voltage

[selldoor]

Re: Possible 2SD1802 replacements?

Got it - My
There are these
http://my.mouser.com/ProductDetail/O...04DRDqYdE2K4I=

perhaps you can find another local outlet with lower delivery?
Best to change all 4 and also reflow transformers and and high voltage blue caps


or this
http://my.element14.com/sanyo/2sd180...251/dp/1790313

[lexwalker]

Re: Possible 2SD1802 replacements?

It would be a great help if you were to update your profile with country and mains voltage

Updated. One the reasons for that 2SC5707 selection is I've had came across this one many times in many monitors with the same Royer configuration...

Got it - My
There are these
http://my.mouser.com/ProductDetail/O...04DRDqYdE2K4I=

perhaps you can find another local outlet with lower delivery?
Best to change all 4 and also reflow transformers and and high voltage blue caps

Yeah, I knew Mouser had it but the shipping plus sales and import tax makes it not that worthy consideration (since used 15" LCD monitors are pretty much dirt cheap over here). Farnell/element14 and RS Components (and sometimes eBay) are my current source most of the time (even though I had an account with Mouser)...

or this
http://my.element14.com/sanyo/2sd180...251/dp/1790313

Hmm... I don't think that one is correct (as I've known Farnell/element14 had put wrong specifications on a number of components on their website). That "...S-TL-E" designation places this model as TO252 package according to the datasheet here:

[lexwalker]

Re: Possible 2SD1802 replacements?

Updated. One the reasons for that 2SC5707 selection is I've had came across this one many times in many monitors with the same Royer configuration...

An update on that. Found a few 2SC5706 (same type as 2SC5707 but with lower amperage, 5A instead of 8A) from some scrap ancient monitors in my storage room. Decided to try it out and it works! Also replaced those 100nF 100V film capacitors (with new ones) in there just in case (don't want another transistor brown out).

A bit of further information concerning the repairs: The inverter section has lots of dry/cracked solder joints which include the leads on the failed transistors (center lead had a clear cracked solder joint) and a few leads on the transformer (a little harder to see, requires bright lights besides magnifying glass). Resoldered most of them, and just in case resoldered the working side as well...

Well, it seems that with these Royer circuits, can use either 2SC5706 or 2SC5707 as replacements...