Who can repair a 48K Spectrum?
My Spectrum is broken, please see: http://www.worldofspectrum.org/forums/showthread.php?t=29351&highlight=7805+heat+sink&page=2
Does anybody know a reliable spectrum repair service?
Does anybody know a reliable spectrum repair service?
Post edited by Alien 8 on
Comments
I did wonder that, I am a bit reluctant though. It has had Womble's composite video mod done, and I really don't want to muck about with that again, but would be reluctant to lose it.
Also, unfortunately I am not well versed in the use of a soldering iron.
(I have about 20 Speccies that I've repaired)
If so these do blow and the result is a computer that simply will just show no life.
These regulators are still being made and easy to find, there are only 3 pins to solder. They are also dirt cheap to buy.
Just take it to any PC repair shop and they will fix it for you :wink:
No, it's not the 7805. The computer shows signs of life, but it isn't useable (colour mosaic etc). I think it is as a result of the 7805 being replaced badly.
I have bought a Spectrum + with composite video conversion as a replacement, but at some point in the fairly near future, I will probably take Spirantho up on his kind offer to get this one working again too.
I wonder if anyone might know what has happened though?
In both cases I attached DivIDE+ to edge connector, with AY sound card on through connector, and D'Ktronics Kempston interface on the back of that. This has always worked fine before. I loaded Knight Lore and the character went berserk, this doesn't normally happen, but happened on both occasions recently. I tried the other socket, that didn't work at all. I took the AY card off the back of the DivIDE+ and put the D'Ktronics interface straight onto the DivIDE+. When I switched on I got a fuzzy black and white garbled screen, so I switched off. I disconnected the D'Ktronics interface and tried switching back on, the DivIDE+ did not boot up, but the power light came on. I disconnected the DivIDE+ and switched the spectrum back on and all I got was 4 vertical black and white bars filling the screen, sometimes with random colour mosaic dotted here and there. That is exactly the same for both Spectrums, the only difference is that the Rubber Key one has some slightly different symptoms, but I am guessing that is down to issue number. The only reason I tried the same thing on the Spectrum + is because my father in law had done a rplacement on the 7805 on the rubber key one, and I thought that the fault maybe related to that. I am now thinking it points to the D'Ktronics interface. The only other connections made were, power, composite video, and a cable from mic to the mono RCA plug on the front of my tv. All connecting and disconnecting was done with the power switched off.
Does anybody have any ideas? The 48 K version gives varied results, usually displays the Sinclair copyright message, although this is sometimes at the top of the screen and 8 groups of dots appear in squares , 4 at the top, and 4 at the bottom of the screen. Sometimes it has a colour mosaic and blue and red loading lines in the border.
Infuriating to have had a perfectly working Spectrum again only for it to be knackered by a D'Ktronics interface (so it seems).
www.rwapsoftware.co.uk
www.sellmyretro.com
Could be, I did wonder about that myself. The only thing is, it worked fine on your Spectrum, it worked fine on my Rubber Key Spectrum to begin with. It only went wrong on that after the 7805 being replaced, to which I attributed the fault, now it seems incorrectly. It is very strange that it has gone from working perfectly to sabre man going berserk in Knight Lore, and then when I connect the interface straight to the DivIDE+ edge connector it appears to have killed 2 Spectrums. It is weird that it happened identically on both. I wonder if something has come loose on the D'Ktronics interface or if there is a problem with the edge connector on the DivIDE+?
Which is why I put weak pull-ups (~47K ohm to +5V supply) on important control signals like /MREQ, /IORQ, /RD and /WR in projects where I create add-on hardware for 8-bitters like the Spectrum (pull-ups inside the add-ons, not the Spectrum). A loose contact then has that signal pulled to 'inactive', which may cause a hang but no hardware conflicts. Last place I did this was an MMC/SD interface for the MSX, and it made the system noticable more hang-proof when wobbling the cartridge in its slot (important for swapping SD cards on systems where cartridges aren't held in place tightly).
No clue what happened here though, but I doubt it's power-related. Overloaded power supply may cause instabilities, but either a voltage regulator is killed entirely or the effect is temporary (=fixed when you remove what was too much). A look at the edge connector(s) / insides of those add-ons might be in order. :confused:
I must admit, I was surprised that this seems to have caused a permanent problem. It seems that something has actually damaged something inside the Spectrum. To be 100% clear this fault persists with nothing plugged into the edge connector.
I looked inside the D'Ktronics interface. Now I am no electronics expert, but I think I spotted something unusual. There was a yellowish/orange component which stands on two legs and is vaguely oblong (although I have seen round ones before). Anyway, on both sides it has a whitish powder appearing to be stuck to it, looks like it may have leaked out. I don't know if this could affect anything, or if it is just historic dirt, but I thought I'd mention it just in case. I can't really think what could go wrong with a joystick interface to be honest, but I suppose something could.
I am tempted to modify some of my machines to "interface 0" so it draws no power
http://www.users.globalnet.co.uk/~jg27paw4/yr05/yr05_72.htm
That looks like a good modification. I don't think I'll be doing it though, modifications was the first step in what led me to having two dead spectrums in the first place! Well, if whoever repairs them could do it, then I probably would go for it.
I am off to photobucket now so that I can upload a picture of the 2 port D'K tronics interface.
Thanks Fog.
www.rwapsoftware.co.uk
www.sellmyretro.com
Please see below:
I have ringed it, but it isn't very clear. Maybe if you look at the original picture, now you know the component in question, it is clearer. I think the red makes it harder to see.
I did thankyou Macc, both working perfectly now, and with a new DivIDE+ unit as well (the other one got blown into the bargain too!). The system is better than it ever has been, so very pleased.
The Spectrum + is a big improvement over the rubber key version, you will be pleased to know that is the machine that I use most of the time now. Although my rubber key spectrum works fine now, it doesn't seem to like the DivIDE+ interface, whereas your old spectrum+ is rock solid with it. I got the spectrums back a week ago, and the DivIDE+ arrived on Tuesday, so I am now having fun reliving the past.
Glad you contacted me, I was meaning to let you know they were fixed now.
Both machines had to have new boards apparently, but they did a great job, they even put the composite video mod on the replacement boards for me.
It wasn't too bad as it happens, thanks for your concern. Now I have got the Spectrum + working again, and a new DivIDE+ unit, I can't reccommend it highly enough, they are brilliant. I never had the full benefit before as either my Rubber Key Spectrum or the DivIDE+ unit (or both) were a bit dud and it was not a happy marriage. It's still a mystery what caused it.