Re: HP dc7800 bad caps

Hi Chaps, Just a follow on this thread I have 3 dc 7800 Towers which all have started to behave "strangly" My problem was with the faster PC6400 RAM installed the graphics would get corrupted and hence the machine would hang up completly! Visually the only capacitor which had bloated was that OST (1500uF 6.3v) one near the RAM slots see jakah fig 1. It was my belief that the higher clocking ram places more current demand on the supply to the RAM and hence the faster RAM which demanded more current would fail whereas the slower RAM which had less...

Re: Acer AL2416W Monitor

Oh yes, Newark, I have come across that name before! It would be so much simpler to use the same name throughout the world don't you think? Or would that be too easy! As for the cooking of the ribbon cable going by the size of the fuse on the "t-con board"of which I still know nothing about! Furtermore, I can't see any reference to it in the service manual either! Each condutor could be carrying 750 mA it would only take a slight imbalence / build up in one contact resistance to start dissipating watts and hence heat the whole show up! It may be...

Re: Acer AL2416W Monitor

Thanks for that, I would post some pictures but they would be very similar to thoes already posted. I forgot to mention I used Rubicom 35ZLH100MEFC6.3X11 From RS Components here in the UK. For you chaps over the pond, Farnell or element 14 as they are now called stock the same part. I chose these for their low ESR and long working life! I believe the manufacturer of the originals was really pushing his manufacturing skills making such a small component in the first place. As mentioned in previous posts a similar size replacement is unavailable. But the longer...

Hi everyone, I took the liberty of starting a new thread on this monitor as recently I have had 3 of these little beasties to repair! All wihin about 1 month which I guess is good in a way as the circuitry and dismantling is still fresh in your mind! The first two of them were pretty straight forward with the usual 100uF 35v Nk com capacitors being the primary cause. One just on the edge would start when warm but as already mentioned, in previous posts, when cold ESR increases and the monitor would not start up at all. The 4 capaitors siliconed togeter each measured out at approximatly 85uF each....

Re: Bad caps often a symptom, not a cause

Having read all of the posts on this subject and at the risk of being accused of sitting on the fence basically you are all right! Yes just changing any suspected capacitors and expecting 100% success is foolish. However having been in the industry for almost 40 years the basic principles have not changed since valves or vacuum tubes as some say. I was always taught to repair / establish correct psu voltages before proceeding to the main circuitry this is particularly important in say dc amplifiers, long tailed pairs etc. and as for the...