Need help reading schematic

I found a fix for my son's crashed Seagate Barracuda 7200 series hard drive, but it requires a COM Port Cable to work. I have a schematic of the cable, but have been unable to get any help from the company that provides the software. I want to make sure that the capacitors are set in the right direction and have a question about 2 of them. One connects the V- from the MAX232 IC to ground and the other connects the V+ from the same IC to VCC (power). Also, on the 78L05 positive voltage regulator, I want to make sure that I have the correct order of the leads, making sure that the input and output are accurate. I can attach the schematic, if I knew how to do so. I have it as a GIF file. This COM Port Cable attaches to the computer with a DB9 plug then goes through the 78L05 & MAX232 before exiting into 3 wires that attach to 3 of the hard drive's jumper pins. I'd appreciate help from anyone who is familiar with electronic schematics. The program is Salvation Data's K7DEMO.

 

Am I seeing 6 capacitors on that schematic, as well as 3 diodes? Which 2 capacitors are you questioning? Is one of them C2? What brand capacitors do you have? Is there any indication of flow direction on them? In many situations the direction doesn't matter much.

On the 78L05, pins 2 & 3 are incoming and 1 is outgoing, based on the diode configuration.

 

Thanks for your response. Yes, there are 6 capacitors and 3 diodes. I assumed that C2+ was + and C2- was -. Let me know if that is incorrect. I figured C1+ to be + connected to C1- as -. I figured the capacitor between the diodes is + towards the 2 diodes and - towards the LED. I figured that the capacitor between the VCC and ground is + on the VCC side and - on the ground side. The remaining 2 are the ones that I'm questioning, though let me know if I misjudged any of the others, are the V+ (#2) to VCC (#16) and V- (#6) to Ground (DB9 #5). On the 78L05, I read #2 as ground with the others as input and output, but is the flat side up in the diagram, with #3 being towards the DB9 and #1 towards the MAX232?

 

78L05 = IC1
Max232 = IC2

Lets just start with C1 and work up. I believe you had C1 correct. C1+ connects to diode side (incoming from DB9 pins 4 and 7); C1- connects to LED (in) side.

C2+ connects to line between IC1 pin 1 and IC2 pin 16; C2- connects to line between LED (out) and IC2 pins 11, 13 and 15 and black (out) to HD

C3+ connects to IC2 pin 16 and C3- connects to IC2 pin 2

C4 and C5 ....... toss a coin I guess

C6+ connects to DB9 pin 5 and loops to LED outgoing (IC2 side); C6- connects to IC2 pin 6

Not knowing your level of knowledge in the area of electronics, I caution you to connect the diodes correctly. While they prevent current flow in one direction, apply power to the wrong end and they pop (like a firecracker, but without the power of one) only once, then they're done.

 

C3 and C6 were the ones that had me lost. I appreciate the answer. You said to toss a coin for C4 and C5. Wouldn't it make a difference? I figure that since IC2 pin 1 is C1+ and pin 3 is C1-, while pin 4 is C2+ and pin 5 is C2- (according to Maxim), that I should attach the C4+ to pin 1 and C5+ to pin 4. Here is what Maxim says:
Pin signal name model name
1 C1+ C1P
2 V+ V+
3 C1- C1N
4 C2+ C2P
5 C2- C2N
6 V- V-
7 T2OUT TOUT
8 R2IN RIN
9 R2OUT ROUT
10 T2IN TIN
11 T1IN TIN
12 R1OUT ROUT
13 R1IN RIN
14 T1OUT TOUT
15 GND GND
16 VCC POWER

I understand the issue of directionality for the diodes, knowing that the arrow points towards -. Are you saying that directionality for capacitors isn't important? I'm no expert here. I've just picked up bits and pieces while working on projects with my son. To make sure I am reading this correctly, I assume that in looking into the female receptacle side of the DB9, that the openings are numbered 1-5 across the top from the right to the left.
I still have one question left regarding the 78L05. In the schematic, is the flat side facing up or down (so I'm sure which is pin 1 and which is pin 3)?
Thanks for the help.

 

I have no idea which side is up or down. Are the pins not numbered (look very closely)? The schematic I'm looking at was downloaded with their demo package, and the pdf has the same one. It doesn't have + and - marked either, which is why I had no way of knowing which pins are + and which are -. The pins aren't marked as C1, or C9 either, only numbered. Since you do have documentation of that, then yes, C4+ would be on IC2 pin 1 and C5+ would be on IC2 pin 4

Polarity for many capacitors is important, and when it is they are generally distinctly marked.

Holding the DB9 connector in your hand, looking at the pin side, five pin side to your right 4 pins to your left, pin 1 is the bottom right, pin 5 top right, pin 6 bottom left and pin 9 top left.

 

Sorry for the delay, but the windowsbbs.com site was down.
I'm assuming that you are talking about the receiving side of the female DB9 receptacle when you described pin 1 as the bottom right. Please confirm this.
I checked the78L05 with a magnifying glass and can't see any numbering. According to the data sheet from ST Microelectronics, the numbering seems to be the opposite of what is in this schematic, unless it is flat (numbered) side down. It shows the output to be pin 1 on the left side with the flat side up. http://www.datasheetcatalog.com/datasheets_pdf/7/8/L/0/78L05.shtml
I'd hate to install it backwards.
It's too bad that this schematic isn't drawn clearer and that Salvation Data won't help more than say to read the schematic.

 

By your discription of 'flat side' I am assuming you have the TO-92 style 78L05. With the flat side down, pins toward you, pin 1 would be on your right.

On the DB9 connector, yes. Looking at the pin side (whether male or female) with the 5 pin row to your right and 4 pin row to your left, pin 1 would be the bottom right.

 

Some info regarding the program and cable.

http://www.salvationdata.com/downloadsFile.asp?di=23

http://www.salvationdata.com/

 

Yes, I do have the TO-92 style 78L05. So, I understand that pin 3 (input) connects with the DB9 and that pin 1 (output) goes to VCC (pin 16) on the MAX232. If that is correct, I believe I have all I need to put this thing together. After confirmation of this information, my son and I will build this contraption tomorrow and see how this miracle program actually works. Though it was a bit of a challenge to read this schematic, my $1.50 cost for the materials beats Salvation Data's $50 cost for a pre-made COM Port Cable. By the way, though the MAX232 is very difficult to locate in my area, Maxim will send out free samples from Asia. I'll report the results here when we've completed everything. Thanks for all the help.

 

Yes ..... pin 3 is DB9 side. Best of luck to ya!

 

Unfortunately, it looks like I'll need some more assistance from you, as Salvation Data isn't responding to any of my emails. The COM Port Cable is complete, though it looks more like a spider web than a cable. I'm sure it will work fine. For this program to work, Win98 must be installed on a FAT32 C drive. Luckily, anticipating this possibility, I install different partitions on my hard drives, with the C drive being a 3GB FAT32 partition. My D drive has WinXP. Tech support at Salvation Data sent me a link, previously, for a download of only those parts of Win98 that are required. Unfortunately, the link doesn't seem to be connecting me to anything. It is http://www.salvationhdd.com/En_resource_downloads/sysiso-en.rar
Would anyone know of a working link to this download?
Also, I need some clarification on using the COM Port Cable. Based on the following link for the numbers of the jumper pins on the drive to repair, this is how I am interpreting Salvation Data's picture. http://eshop.macsales.com/Tech/manuals/idehdsettings/Seagate72.pdf
I assume that the black lead goes to pin #7, the red lead goes to pin #3 and the yellow lead goes to pin #4. Please let me know if this is correct.
Also, should the drive to be repaired be jumpered as cable select during this repair process, and should the IDE cable be attached during the repair process. Unfortunately, Salvation Data's instructions aren't all that clear. Hopefully, you are able to understand them better than me.

 

Hi Barry,

I was unable to locate the win98 download package as well. Are you positive win98 is required? I know the pdf says that, but that was last updated in 2005 too. Thought I saw something in their forum about it working from XP now. BTW, installing win98 (it has to be at least somewhat functional install to work, IMO) on a system currently running XP can be quite tricky, as the boot sector gets re-written. Proceed on the side of caution and be darned sure what you're getting into first.

I believe you've got the pin assignment right. There are no jumpers attached with this setup from what I can tell. Remove all jumpers first, then connect your com port cable.

Looks also that all data is transfered via the com port cable, so no IDE ribbon cable required either. You will attach the 4 pin power supply connector.

 

Thanks for your help. When I was last able to communicate with Salvation Data tech support, back in October, I was told that Win98 was necessary. Here is our correspondence:

Me: The owner's manual says that this only works with Win98. Do I need to install Win98 on a partition, or can it run on WinXP?

Salvation Data: About the system, Win98 is ok. Or we can provide a ghost iso for you. The download link for the ghost iso:
http://www.salvationhdd.com/En_resource_downloads/sysiso-en.rar
Just download and use the system iso that I've given the link to you. You don't need to a whole win98 cause it will waste your time.

It also needs to be located on the C partition, and my XP is on my D partition.

Here is some information I picked up on the web. Would this Win98Lite be the same as the ISO?

can be download some win98 lite from just do a google search, win98lite only need 7mb, full fuction minus some no use security,

http://www.litepc.com/

http://bochs.sourceforge.net/doc/docbook/user/guest-win98.html

 

Sure wish I could get my hands on that iso .... I'm curious about it's contents. Since you didn't mention that you have XP, I would certainly get back with them and ask specifically if the software version you have will run from XP, and that the OS is on D: rather than C:

 

I did run that by him, but it was hard to communicate, as his primary language is Chinese. I wish I was able to connect again, but all I can do is reach out. Did you see the additional info I added to my last post about Win98Lite? What are your thoughts about that?

 

Salvation Data has fixed the link. It is http://www.salvationhdd.com/En_resource_downloads/sysiso-en.rar.
It is a 4.16mb file.

 

Interesting. It is a ghost file (system.GHO). I'll have to set up one of my old HDDs to set it up on.

 

Barry, do you by chance have an extra hard drive you could use? I would be very hesitant to put a 98 image on C: while having XP installed on D: ........ what happens to the MBR?