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Component Equivalents/substitutionsA while ago, I mentioned to somebody in a thread that we should have a list of component equivalents and substitutions so that it's easier to fix our…
... works in place of ZTX450, TR7, Issue 3+
ZTX651 works ... -
Erratum in Spectrum schematics?Forgive me if this is old news, but I have recently adquired some new microspeakers for repairing damaged ones in various Spectrums. One of these had…
... Spectrums. One of these had TR7 missing. When I was to ... .) I discovered that collector of TR7 is not tied to +5V ... -
Quiet ZX Spectrum Issue 3We have a ZX Spectrum issue 3 where the volume is very low. The TR7 has been replaced, but to no effect. The speaker looks ok, but apart from swapp…
We have a ZX Spectrum issue 3 where the volume is very low.
The TR7 has been replaced, but to no effect. The speaker looks ok, but apart from swapping the speaker, is there anything else to try? -
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…
... ]
TR4, TR5 and TR7 (all type 2N3904) are fitted ... 23 of the "ULA").
TR7 is the transistor that pulls ... ]PS Does anyone know why TR7 being fitted incorrectly appears to ... -
Project #1 : Speccy 128k+2 with diVide inside...Hi guys, I just have finished my Super Spectrum #1 The idea (I was thinking of that since 2007) was to fit an english grey +2 motherboard in a +2A…
... refit the TR4, TR5 and TR7 (2N3904) the right way. Picture ... -
+2 Grey ropey RF[url=http://postimg.org/image/y9s0xc5k5/][img]http://s18.postimg.org/y9s0xc5k5/P180413_13_13.jpg[/img][/url] Re-orientated TR4 as per normal but the …
[url=http://postimg.org/image/y9s0xc5k5/][img]http://s18.postimg.org/y9s0xc5k5/P180413_13_13.jpg[/img][/url]
Re-orientated TR4 as per normal but the RF is awful on this CRT, would it be wise to do TR5 and TR7? Would that improve it any? -
48K loudspeaker questionsI wonder if someone would know what "40 ohm T.V. type" means? This is the description of the 48K loudspeaker given in the service manual. I?d also li…
... I read that more likely TR7 and D9 die, before the ... -
48k no beeper sound (again!)Got three 48k+ here, all of which have the same exact problem, no sound out the beeper, same problem as detailed [URL="http://www.worldofspectrum.org…
... known worker, they work. Replaced TR7 with a ZTX651, same, tested ... -
Issue 3B no soundI just noticed that there's no sound in the Issue 3B Speccy that I've been fixing. Is it more likely that the speaker is bust or is it TR7 and D9? …
I just noticed that there's no sound in the Issue 3B Speccy that I've been fixing.
Is it more likely that the speaker is bust or is it TR7 and D9? Or both? -
ZX Spectrum+ DivMMC EnJOY! Grundig 16" LCD TV and books.The Spectrum is in very good condition. Composite video mod. New mambrane (bought in November 2014 from rwap_software [url]http://www.sellmyretro.co…
... : 42 ohms in-circuit.
- TR7 & D9 test OK in ... ,2.
- No signal at TR7 base. Suggests D9 is faulty ... -
2n3904 equivalentsI could of sworn i had plenty of these but all im coming up with is bags of 2n2222's, im guessing these wont be drop in replacements right? This is …
I could of sworn i had plenty of these but all im coming up with is bags of 2n2222's, im guessing these wont be drop in replacements right?
This is for TR7 in a french grey +2 btw -
Replacement speakers for 16/48K SpectrumsThought I'd share a source of replacement speakers for the 16/48K machines: http://uk.rs-online.com/web/p/miniature-speakers/7903975/ (Equivalent…
... directly from the ULA (no TR7), so if fitting one to ... -
ZX Spectrum 48K Issue 4B No soundHi, I have a ZX Spectrum 48K Issue 4B without sound. I tested the ULA on another Spectrum and works fine, tested the speaker and it has the correct …
... ULA to emitter of TR7 no faults. TR7 tested ok. The only ... is that the collector of TR7 has +10V and it's ... -
Profile of a Spectrum user...Whilst watching Crimewatch on the telly, there was something on there about certain criminals fitting lifestyle profiles... Is there a profile of a …
Tomb Raider - LegendSeven and a half hours. Seven and a half bloody hours. Seven hours and a tad over thirty mins TOTAL. Great Graphics. Great Story. A GRAND TOTAL …
... joke. It's crap. So TR7 doesn't sound like it ...Tomb Raider - LegendSeven and a half hours. Seven and a half bloody hours. Seven hours and a tad over thirty mins TOTAL. Great Graphics. Great Story. A GRAND TOTAL …
... [url=http://worldofstuart.excellentcontent.com/tr7/tomb.htm]Stuart Campbell's ...Note to SpiranthoIan Whilst playing about with Frankenspec, I have discovered that the 41256 memory IC works as well as a 4164 (etc) in the upper RAM block of a 48K …
BA158 fast recovery diodes work in place of the BA 157.
ZTX650/651 works in place of ZTX450, TR7, Issue 3+
Ian, you have a PMtr1-2-3-4-5hi guys, can someone tell me, what is the exact function of each of the five transistors i have on my zx+3 i mean the black transistors TR1 TR2 TR3 T…
... /> You must be reffering to TR7, thats the one for audio ...tr1-2-3-4-5hi guys, can someone tell me, what is the exact function of each of the five transistors i have on my zx+3 i mean the black transistors TR1 TR2 TR3 T…
... /> You must be reffering to TR7, thats the one for audio ...sinclair zx spectrum issue 6a (again) - how to repairHi All, Is there someone who may explain what these jumpers can be used for. [url]http://forest.no-ip.org/repair/jumpers.gif[/url] <- this is from …
... response to A0 going high). TR7 is used to switch 9V ...issue 4s for reapirHi All, This time I have issue 4s for repair :) Here is few screen shots and small movie after boot. [url]http://forest.no-ip.org/issue4s/[/url] I kn…
... /> tr5 = a733 (y-3d5)
tr7 = d471a (y-3d6)
tr1 ...Replacement loudspeaker for rubber key 48kI'm fixing one of my rubber key 48k. Just ordered a membrane for it but I also need to find a replacement loudspeaker for it. The original some how q…
... the music was playing, the TR7 transistor (ZTX450) was getting really ... .... absolutely no heat on the TR7 this time and the sound ...Quiet ZX Spectrum Issue 3We have a ZX Spectrum issue 3 where the volume is very low. The TR7 has been replaced, but to no effect. The speaker looks ok, but apart from swapp…
... this:
- Check if TR7 has +5V at the collector ...ZX 48K loudspeaker with 8 Ohm possible?Is it possible to change the loudspeaker from the ZX 48K with a model which has only 8 Ohm? Micky
Possible, but not recomended, as TR7 (ZTX450) will have to sink ... speaker.
SIDE NOTE: TR7 is configured as an emitter ... the risk of damage to TR7.
BTW: I sucessfully ...ZX 48K loudspeaker with 8 Ohm possible?Is it possible to change the loudspeaker from the ZX 48K with a model which has only 8 Ohm? Micky
... ]Possible, but not recomended, as TR7 (ZTX450) will have to sink ...ZX 48K loudspeaker with 8 Ohm possible?Is it possible to change the loudspeaker from the ZX 48K with a model which has only 8 Ohm? Micky
... />
You are assuming that TR7 saturates, but is that true ... ? TR7 is configured as an emitter ...ZX 48K loudspeaker with 8 Ohm possible?Is it possible to change the loudspeaker from the ZX 48K with a model which has only 8 Ohm? Micky
Which transistor works with a 8 ohm loudspeaker? I mean I take the other transistor instead TR7.
MickyDo ULAs die?Thought I'd start this thread as people often think their ULA is dead, when it's actually the RAM or power circuits. Searching the forum in the futur…
... , as well as emitter follower (tr7) and d9 in the speaker ...ZX Microdrive endlessly spinningHi, I've got 2 ZX Microdrives that behave very similarly, basically they seem to be receiving commands nicely, but no matter whether i LOAD SAVE or …
... /> Continuous running MDV1(MDV2). Renew TR7(TR6)Mute switchOn a standard 48K machine, would it do any harm to fit a mute switch into one of the sounders connections ? I mean by 'harm' switching it on / off w…
... that, as you will stress TR7 with a high current condition ...
