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Fixing my old ZX Spectrum 48K issue 4AHi Guys, I trying to fix my old Spectrum 48K. Looks like my dad used a wrong power supply as the ULA had a bit missing and so did the 7805. So I rep…
... oscillation circuit formed by the coil/TR4/TR5.
B ... -
AAAARRRRR DIV-MMC ENJOY againIve recently been posting trying to get to the bottom of problems with my +48 not working with this rechid addon.Now ive finaly worked out theres not…
... being just left of the coil and TR9 just above and ... to the left of the coil.
Markings on the ... -
ZX Spectrum 48K Issue 3, loss of -5V rail.Hi all, I've googled this problem and poured over the electrical diagrams for the circuitry concerning the power supplies and I believe I know what …
... rail it could be the coil... is it whistling?
coil to answer your original question ... re coil voltages, but there's several ... -
ZX Spectrum 48K Issue 3, loss of -5V rail.Hi all, I've googled this problem and poured over the electrical diagrams for the circuitry concerning the power supplies and I believe I know what …
... good, then it's the coil or a RAM chip. Change ... the coil next - it's easier than ... the electrolytics first, then the coil, though. -
ZX Spectrum 48K Issue 3, loss of -5V rail.Hi all, I've googled this problem and poured over the electrical diagrams for the circuitry concerning the power supplies and I believe I know what …
... at one end of the coil will be the same as ... the other end of the coil should be an AC voltage ... -
ZX Spectrum 48K Issue 3, loss of -5V rail.Hi all, I've googled this problem and poured over the electrical diagrams for the circuitry concerning the power supplies and I believe I know what …
... to change the capacitors and coil. I believe the Zener diode ... work, we all believe the coil should be first thing to ... -
ZX Spectrum 48K Issue 3, loss of -5V rail.Hi all, I've googled this problem and poured over the electrical diagrams for the circuitry concerning the power supplies and I believe I know what …
Just try changing C46 (1uf, 50v) first, if you're sure about the Zener. I've seen this take out a -5v rail also.
I've not known a coil failure to take out -5v without also losing +12v, although stranger things have happened.
B -
ZX Spectrum 48K Issue 3, loss of -5V rail.Hi all, I've googled this problem and poured over the electrical diagrams for the circuitry concerning the power supplies and I believe I know what …
... ?
I noticed my coil does indeed a hissing noise ... all the above (TR4, TR5, coil, diode) is in good working ... -
ZX Spectrum 48K Issue 3, loss of -5V rail.Hi all, I've googled this problem and poured over the electrical diagrams for the circuitry concerning the power supplies and I believe I know what …
... :)
Noise from the coil is normal, especially on issue ... -
Help put this back to 16kSo this issue 2 arrived today and ive opened it up just to nosey and confirm that infact it is an issue 2. Now from the help offered in an earlier po…
... poking around i noticed the coil was slightly melted:x ,i ... maybe 2 transisters and a coil but when alls said and ... -
Help put this back to 16kSo this issue 2 arrived today and ive opened it up just to nosey and confirm that infact it is an issue 2. Now from the help offered in an earlier po…
... correct.
The inductor coil rarely fails, but if it ... -
Help put this back to 16kSo this issue 2 arrived today and ive opened it up just to nosey and confirm that infact it is an issue 2. Now from the help offered in an earlier po…
ive just noticed i dont know if it makes a difference but in one of the pictures i posted a above there is a break in the solder on the leg of one of the caps next to the coil,picture also shows the state of the coil. -
Help put this back to 16kSo this issue 2 arrived today and ive opened it up just to nosey and confirm that infact it is an issue 2. Now from the help offered in an earlier po…
... & TR5 and the inductor coil. Replace any components found to ... -
ZX Spectrum 48K Issue 3, loss of -5V rail.Hi all, I've googled this problem and poured over the electrical diagrams for the circuitry concerning the power supplies and I believe I know what …
... seeing either side of the coil for comparison, but after reading ... -
ZX Spectrum 48K Issue 3, loss of -5V rail.Hi all, I've googled this problem and poured over the electrical diagrams for the circuitry concerning the power supplies and I believe I know what …
ZX Spectrum 48K Issue 3, loss of -5V rail.Hi all, I've googled this problem and poured over the electrical diagrams for the circuitry concerning the power supplies and I believe I know what …
[QUOTE=Renegade;784026]Coil? TR4 or TR5?[/QUOTE]
< ...Composite picture qualityI have read many many discussions here about the composite video modification of the Spectrum 16/48K models. I have choosen one of the simplest comp…
I inserted a 220 uH coil in the +12VA line going ... of R62 and put the coil between R62 and board). That ...Composite picture qualityI have read many many discussions here about the composite video modification of the Spectrum 16/48K models. I have choosen one of the simplest comp…
... ]I inserted a 220 uH coil in the +12VA line going ... of R62 and put the coil between R62 and board). That ...Spectrum 48k ProblemsHi all Got my 48k today but it's playing up abit... First time i turn it on it was like this: [IMG]http://s26.postimg.org/hlg9d3f3d/IMG_20140830_…
... .
Is it the coil? DC socket? I'm leaving ...Spectrum 48k ProblemsHi all Got my 48k today but it's playing up abit... First time i turn it on it was like this: [IMG]http://s26.postimg.org/hlg9d3f3d/IMG_20140830_…
It's the coil, these tend to make noise particularly on issue 2's. What I hear from yours is normal.
BSpectrum 48k ProblemsHi all Got my 48k today but it's playing up abit... First time i turn it on it was like this: [IMG]http://s26.postimg.org/hlg9d3f3d/IMG_20140830_…
... there anyway to stop the coil making that noise? I hate ...Spectrum 48k ProblemsHi all Got my 48k today but it's playing up abit... First time i turn it on it was like this: [IMG]http://s26.postimg.org/hlg9d3f3d/IMG_20140830_…
... will.
Regarding the coil, I view the noise as ... clear nail polish on the coil windings can help, although it ...Wanted: Case for ZX Spectrum (16/48/48+)Hi, I've been kindly given a project by a forum member which is gratefully received. I'm looking for some kind person to give/sell a spare shell c…
Glad to see you're going to try and get it working again. Hope it goes well. It will need a replacement coil i know that much (I'm sure you noticed this already).Wanted: Case for ZX Spectrum (16/48/48+)Hi, I've been kindly given a project by a forum member which is gratefully received. I'm looking for some kind person to give/sell a spare shell c…
... . It will need a replacement coil i know that much (I ...Early ZX80/81 RAM Pack???Hey all I got given this RAM pack... It doesn't work (i know why now) but compared to my RAM pack this one is really strange... Is this a ZX80 RAM p…
Nope, that's an early model ZX81 RAM Pack. I have one that's identical.
No idea on the coil end of things, unfortunately.
BEarly ZX80/81 RAM Pack???Hey all I got given this RAM pack... It doesn't work (i know why now) but compared to my RAM pack this one is really strange... Is this a ZX80 RAM p…
Ah ok nice. Any idea if i can buy a replacement coil for this?Early ZX80/81 RAM Pack???Hey all I got given this RAM pack... It doesn't work (i know why now) but compared to my RAM pack this one is really strange... Is this a ZX80 RAM p…
Yup as Balford said Issue one rampack and the coil like the coil in the speccy provides one of the voltages for the ram chips 12v I think.Early ZX80/81 RAM Pack???Hey all I got given this RAM pack... It doesn't work (i know why now) but compared to my RAM pack this one is really strange... Is this a ZX80 RAM p…
If its the same as the speccy coil here might be a good place to look about two thirds down the page.
[url]http://www.bytedelight.com/?page_id=9[/url]C46 Capacitor MarkingHi all I've just watched this part of this video: [url]http://www.youtube.com/watch?v=TeCVt2T-YSo&t=17m0s[/url] And he says the marking is incorrec…
... TR4 and one of the coil windings. The negative terminal is ...C46 Capacitor MarkingHi all I've just watched this part of this video: [url]http://www.youtube.com/watch?v=TeCVt2T-YSo&t=17m0s[/url] And he says the marking is incorrec…
... used into a very small coil to hold the leg and ...
