-
ZX Spectrum 48k issuesHi all! A couple of days ago I bought my first 48k Speccy off ebay (I already own a beautiful QL expanded with QubIDE interface and 640k ram). It was…
... checks before power on (continuity, tr4/tr5, coil, power connector) and the socketed ... -
Diag Board and Simple 8bit IDE IFHello, finally I have made it. After finishing Winston's Diag Board a few days ago I started yesterday building the 8 bit IDE Interface from Peras s…
... I got rid of this TR4/TR5/coil technique. But also there is ... -
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 ... />
I have not thouched TR4 or TR5 yet.
If ... that mean all the above (TR4, TR5, coil, diode) is in good working ... -
48k Spectrum "Jail Bars" Removal?Hi all Just curious I think I saw a post here about the bars that go down the screen on some 48k's I think he referred to them as "jail bars". Any…
... )
[*]Several kHz from the TR4/TR5/coil switching circuit
[*]Various frequencies ... smooth the outputs from the TR4/TR5/coil switching circuit would also help ... -
Help changing TR4 and TR5Hi all! Please, help me! :) I think I'm not understanding the correct pins of TR4/TR5 and the transistors. So, if anyone know the correct pins, help …
... understanding the correct pins of TR4/TR5 and the transistors.
So ... and BC307 to use in TR4/TR5.
And I found some ... original pins that?
TR4 TR5 TR4 TR5
E C |\ /|
TR4/TR5 replacementHi guys, I've got another Spectrum I'm working on now - an Issue 4S this time. When I originally got it, I powered it up and did the basic tests a…
... I need to replace TR4 and TR5 in order to get ... I had some confusion with TR4. Looking at all the ... board. Photos show that TR4 should be installed in ... br /> I've since replaced TR4 (marked ZTX650) with a new ... I'm planning to replace TR5 later this afternoon.
...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 …
... one end of the coil will be the same ... other end of the coil should be an AC ... , the internal voltage converter (TR4 and TR5) can fail and ... that the internal voltage converter (TR4 and TR5) has failed.
... and the internal voltage converter is working, but 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 …
[QUOTE=Renegade;784026]Coil? TR4 or TR5?[/QUOTE]
Is the ... the voltage converter circuit is oscillating, then TR4 & TR5 are almost certainly ...'Interesting' Issue 2 modSo I've been lurking on this forum for a while and I've got to the point where I want to see if I can repair a speccy.. so I bought me a 'broken' one…
... designed switch mode circuit (TR4, TR5 and the coil).
What I would ... a second DC to DC converter to supply +12V for the ... =gensearch&Ntt=DC+DC+converter&Ntx=mode+matchallpartial& ...Trying to repair a Speccy 48k - No PulsingI've had this machine for ages. I'd I've been putting off fixing it for some time now. So a couple of days ago I pulled it apart and started prob…
... leaking through the coil of the DC/DC converter/inverter (TR4, TR5 and associated ...ZX Spectrum Test PCB I recently read about one of these (I think it may have been the Retroleum site but I am not sure) and I thought "What a great idea" . As pictured …
... the DC/DC converter/inverter circuitry (TR4, TR5 and the "coil" and associated components ...Correction of +2 hardware errorsThis is a collection of various pieces of information picked up from various places, including a lot from this forum. I have edited it and reworded i…
... errors:-[/B][/U]
TR4, TR5 and TR7 (all type 2N3904 ... they work correctly.
TR4 provides the composite video output ... 6 of the TEA2000).
TR5 provides the vertical Sync. (V ... that is connected with its coil parallel to the motor. Cut ...Almost no picture on a toastrack Issue 6UI?d need some help with a toastrack, that hardly shows any picture on both the RF and RGB. It?s totally distorted. I had this before and I remembered…
... and I remembered that replacing TR4/TR5 did help. However, this one ... transistors are located near the coil, so at a different location ...48k - Why Won't it Buzzzz?Hi WOS ;) I bought a load of Spectrum games off eBay and thrown in for good measure was a 48k 1984 Issue 6a circuit board that I was told was for sp…
... thinking along the lines of TR4/TR5 having been blown, so I ... a wire on the inductor coil was broken! So I desoldered ...Best replacement for ZTX650?What is the best replacement transistor for the obsolete ZTX650? I've read that TIP31 will do the trick. Is there a decent equivalent from the BC or …
... short circuit)
The COIL between TR4 and TR5 (does it look / smell ... voltages are present before the TR4 blows. Check one at a ... />
I replaced tr4, tr5 and the coil but tr4 keeps blowing.
I ... question, can i use the coil of a +2 gray spectrum ...Remove +12 Volt itemsWhich items can be removed on a ZX48K issue 4b PCB if I don't need the +12 Volt? Micky
... YUV to RGB or YPbPr converter.[/QUOTE]
I've got ... ) all the voltage conversion circuitry (TR4/5, coil, various diodes / capacitors etc ...Issue 2 voltage troubleDear all, I got my hands on an old issue 2 from a friend. Price was close to zero so I did not hesitate to take it. After powering it up I was sur…
... :
[LIST]
[*]TR4 or TR5 [I]almost[/I] dead to ... .
[*]Shortened turns in the coil, such that the voltage swing ... just go ahead & replace TR4, TR5 and electrolytic caps.
Colour blocks on displayHi all, I have just acquired another Sinclair product, my first one being a C5, it's a 48K ZX Spectrum. It shows colour blocks on the display when p…
... a problem with the voltage converter circuit or power supply connections ... of the Issue 2 voltage converter circuit failing. If that has ... possible one or both of TR4/TR5 have failed. Carefully note the ...Colour blocks on displayHi all, I have just acquired another Sinclair product, my first one being a C5, it's a 48K ZX Spectrum. It shows colour blocks on the display when p…
... meter readings within the voltage converter circuit. It's much ... that either the voltage converter circuit is faulty or ... concentrate on getting the voltage converter working properly and finally ... shorted its power connections, TR4/TR5 may die and if that ...Issue 4A repair attemptI think I need some help. I have a nice Issue 4A main board here, which does not give out any video signal. I checked some voltages (the ones that se…
... regulator, the coil, the entire lower RAM and TR4/TR5 all show expected ...Issue 4A issuesHi all, I've been trying to get the Issue 4A board that came DOA with the case I purchased for my Frankenspectrum to work. I've recapped and socket…
... , 7805 and coil swapped out, and TR1/TR2/TR4/TR5 swapped for spares ...Almost no picture on a toastrack Issue 6UI?d need some help with a toastrack, that hardly shows any picture on both the RF and RGB. It?s totally distorted. I had this before and I remembered…
Best to renew the electrolytic capacitors in that area, recheck TR4/TR5, then check the coil if all else fails?
BFixing 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…
Hmm, TR4 shouldn't be running that ... oscillation circuit formed by the coil/TR4/TR5.
BFixing 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…
[QUOTE=balford;776165]Hmm, TR4 shouldn't be running that ... oscillation circuit formed by the coil/TR4/TR5.
B[/QUOTE]
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…
... the condition of TR4 & TR5 and the inductor coil. Replace any components ...Next step for fixing my speccy?Hi guys, I've picked up my faulty Spectrum aiming to fix it. So I followed the excellent JouledperCoulomb videos on Youtube for the basics and I am …
... - this means the voltage converter circuit based around TR4 is fine. Since ... volt. At this stage, replace TR4/TR5 if you don't get ... , check the associated circuitry around TR4/5 as the Zener diode ...Next step for fixing my speccy?Hi guys, I've picked up my faulty Spectrum aiming to fix it. So I followed the excellent JouledperCoulomb videos on Youtube for the basics and I am …
... - this means the voltage converter circuit based around TR4 is fine. Since ... volt. At this stage, replace TR4/TR5 if you don't get ... , check the associated circuitry around TR4/5 as the Zener diode ...Faulty 48+ Help NeededHi, This is what I get when I plug in the spectrum, this is tuned in. Vid shows a reset. Any ideas, or pointers on the first thing to check. Keyboa…
... have no buzz from the coil (sick Spectrums with bad voltage ... they don't make the coil resonate - a Spectrum should have ... buzz).
1) Change Tr4/Tr5
If that doesn't ... joy:
3) Change the Coil and Tr4/Tr5 again.
If ...Faulty 48+ Help NeededHi, This is what I get when I plug in the spectrum, this is tuned in. Vid shows a reset. Any ideas, or pointers on the first thing to check. Keyboa…
... have no buzz from the coil (sick Spectrums with bad voltage ... they don't make the coil resonate - a Spectrum should have ... buzz).
1) Change Tr4/Tr5
If that doesn't ... joy:
3) Change the Coil and Tr4/Tr5 again.
If ...'Interesting' Issue 2 modSo I've been lurking on this forum for a while and I've got to the point where I want to see if I can repair a speccy.. so I bought me a 'broken' one…
TR4, TR5, a coil, a power socket, an sr10s05 regulator and some capacitors ordered... exciting! :D
